Design of catalyst-free selective oxidation system for glycerol valorization using nonthermal atmospheric pressure plasma

Monday, April 29, 2024

2:15 PM – 2:30 PM EDT

Room: 518b

Co-Author(s)

TC

Tsutomu Chida

Graduate student
Tohoku University
Sendai, Miyagi, Japan
YN

Yuya Nakagaki

Graduate student
Tohoku University, Japan
SS

Shota Sasaki

Assistant Professor
Tohoku University, Japan
Kousuke Hiromori, PhD (he/him/his)

Assistant Professor
Tohoku University
Sendai, Miyagi, Japan
NS

Naomi Shibasaki-Kitakawa

Professor
Tohoku University, Japan

Presenting Author(s)

Atsushi Takahashi, PhD

Associate professor
Tohoku University
Sendai, Miyagi, Japan

Abstract: In the valorization of glycerol (GL) into high-value materials, selective oxidation is effective, allowing its conversion into pharmaceutical raw materials such as GA. In this selective oxidation, the generation of active oxygen species to progress the reaction is crucial, and studies have primarily been conducted using precious metal catalysts. However, due to concerns for sustainability regarding the use of precious metals, the development of catalyst-free selective oxidation methods is anticipated. Therefore, we are advancing the development of a catalyst-free selective oxidation method for GL, focusing on the sustainable generation of various active oxygen species by irradiating atmospheric pressure plasma to H2O. To efficiently proceed with GL selective oxidation under plasma irradiation, it is necessary to grasp the mechanism of reactive oxygen species generation and GL oxidation. In this study, we constructed a kinetic model considering the generation mechanism of reactive oxygen species under plasma irradiation and combined it with the GL oxidation mechanism to extend it. In this process, 17 elementary reaction processes involving, among others, OOH radicals were considered for reactive oxygen species generation, and for GL oxidation, oxygen addition and dehydrogenation as selective oxidation and degradation as side reaction were considered. Then, the rate constants related to reactive oxygen species generation were estimated through separate experiments without GL addition. Next, using these estimated values, the rate constants related to GL oxidation were estimated with the experimental results. The calculated results from the model were able to represent the reaction behavior of the oxidation products from GL well. Therefore, this model enables to predict efficient GL selective oxidation conditions in the plasma irradiation system.